This invention relates to devices attached to vehicles and employing mud flaps for the purpose of preventing mud, rocks or water spray from being thrown upon following vehicles. A large number of such devices have been devised for semi-tractors and trailers. These structures incorporate anti-sail structures and mounting structures appropriate for semi-tractors and trailers. Such devices are generally too large and unwieldy for small trucks, particularly those manufactured by General Motors Corporation, most particularly the vehicle known as the Blazer.